The invention pertains to the field of jet technology, primarily to pump-ejector units for producing a vacuum or evacuation and compression of various gaseous mediums.
An operational process of a pumping-ejection system is known, which includes delivery of a liquid medium into a nozzle of a liquid-gas ejector by a pump, evacuating a gaseous medium by the ejector, discharging a gas-liquid mixture from the ejector into a separator, separating the mixture into the compressed gas and motive liquid, and delivery of the motive liquid from the separator to a suction port of the pump (see application EP 0783910, MPK 6 B 01D3/10, 29.02.96).
This application also introduces a pumping-ejection system having a liquid-gas ejector, a source of an evacuated gaseous medium, a separator and a pump, wherein the gas inlet of the ejector is connected to the source of an evacuated gaseous medium, a nozzle of the ejector is connected to the discharge side of the pump, an outlet of the ejector is connected to the separator, and the liquid outlet of the separator is connected to the suction port of the pump.
The described operational process and system for its embodiment provide evacuation of a gaseous medium entailing minimal environmental pollution. However this process and system do not ensure sufficient compression of the evacuated gas. Therefore application of additional means for compression of gas is required.
The starting point for the present invention is an operational process of a pumping-ejection apparatus, which includes delivering a motive liquid under pressure into the nozzles of first-stage and second-stage liquid-gas ejectors by a pump, evacuating a gas-vapor medium by the first-stage ejector, discharging a gas-liquid mixture composed of the evacuated gas-vapor medium and motive liquid from the first-stage ejector into a first-stage separator, separating the mixture in the first-stage separator into the compressed gas and motive liquid, feeding the motive liquid from the first-stage separator to the pump, evacuating the compressed gas from the first-stage separator by the second-stage ejector, additionally compressing the gas and mixing it with the motive liquid in the second-stage ejector, discharging the so formed gas-liquid mixture from the second-stage ejector into a second-stage separator, separating the mixture received from the second-stage ejector in the second-stage separator into the additionally compressed gas and motive liquid, delivering the additionally compressed gas from the second-stage separator to consumers, delivering the motive liquid from the second-stage separator into the first-stage separator (see Certificate of authorship USSR 1535114, MPK 6 F 04 F 5/48, 29.09.86).
The same USSR Certificate of authorship No. 1535114 describes a pumping-ejection apparatus having a first-stage ejector and a first-stage separator, a second-stage ejector and a second-stage separator, and a pump. The suction side of the pump is connected to the first-stage separator, the discharge side of the pump is connected to the nozzles of the first-stage and second-stage ejectors, outlets of the first-stage and second-stage ejectors are connected to the first-stage and second-stage separators, respectively, the second-stage separator is connected to the first-stage separator, the gas inlet of the second-stage ejector is connected to the first-stage separator.
This pumping-ejection apparatus provides two-stage compression of an evacuated gaseous medium. However while evacuating a multi-component gaseous mediumxe2x80x94the mixture of hydrocarbon gases and water steam, for examplexe2x80x94the motive liquid accumulates admixtures. This changes physicochemical properties of the motive liquid and negatively affects the capacity of the liquid-gas ejectors.
This invention is aimed at more effective evacuation of a gaseous medium by providing separation of condensable components of the evacuated gaseous medium and by creating optimal operating conditions for pumping equipment of the pumping-ejection apparatus.
The stated objectives are achieved with the use of an operational process of a pumping-ejection apparatus, which includes delivery of a motive liquid under pressure into the nozzles of first-stage and second-stage liquid-gas ejectors by a pump, evacuating a gas-vapor medium by the first-stage ejector, discharging a gas-liquid mixture composed of the evacuated gas-vapor medium and motive liquid from the first-stage ejector into a first-stage separator, separating the mixture in the first-stage separator into the compressed gas and motive liquid, feeding the motive liquid from the first-stage separator to the pump, evacuating the compressed gas from the first-stage separator by the second-stage ejector, additionally compressing the gas and mixing it with the motive liquid in the second-stage ejector, discharging the so formed gas-liquid mixture from the second-stage ejector into a second-stage separator, separating the mixture in the second-stage separator into the additionally compressed gas and motive liquid, delivering the additionally compressed gas from the second-stage separator to consumers, delivering the motive liquid from the second-stage separator into the first-stage separator, and which is modified so that the gaseous medium is evacuated first by a steam-gas ejector, a steam-gas mixture formed in the steam-gas ejector is fed into a counter-flow condenser-separator, simultaneously a condensing hydrocarbon liquid, whose saturated vapor pressure is lower than the saturated vapor pressure of water, is fed into the condenser-separator, the condensing liquid condenses water steam and easy-condensable components of the evacuated gaseous medium while flowing through the condenser-separator, a portion of the steam condensate (water) is discharged from the condenser-separator, a liquid mixture composed of the rest of the steam condensate and the condensate of the easy-condensable components of the evacuated gaseous medium is delivered to an inlet separator, non-condensable components of the steam-gas mixture are evacuated from the condenser-separator by the first-stage liquid-gas ejector, the liquid mixture is separated in the inlet separator into water and the condensate of the evacuated gaseous medium, the water is discharged from the inlet separator, the condensate of the evacuated gaseous medium is delivered from the inlet separator to the first-stage separator, in the first-stage separator the remaining water is separated from the mixture of mediums and then is discharged from this separator, and a mixture composed of the motive liquid and condensate of the evacuated gaseous medium is delivered to the suction port of the pump.
With regard to the apparatus as the subject-matter of the invention, the mentioned technical problem is solved as follows:
a pumping-ejection apparatus, which has a first-stage ejector, a first-stage separator, a second-stage ejector, a second-stage separator and a pump, and wherein the suction side of the pump is connected to the first-stage separator, the discharge side of the pump is connected to the nozzles of the first-stage and second-stage ejectors, outlets of the first-stage and second-stage ejectors are connected to the first-stage and second-stage separators, respectively, the second-stage separator, is connected to the first-stage separator, the gas inlet of the second-stage ejector is connected to the first-stage separator, is furnished further with a steam-gas ejector, a counter-flow barometric condenser-separator and an inlet separator. A nozzle of the steam-gas ejector is connected to a source of compressed steam, the gas inlet of the steam-gas ejector is connected to a source of an evacuated gaseous medium, an outlet of the steam-gas ejector is connected to the counter-flow condenser-separator, the counter-flow condenser-separator is connected to the gas inlet of the first-stage ejector and to the inlet separator, the counter-flow condenser-separator is furnished with a water discharge manifold and a device for feeding a hydrocarbon condensing liquid, whose saturated vapor pressure is lower than the saturated vapor pressure of water, and the inlet separator is connected to the first-stage separator.
In addition, the pumping-ejection apparatus can be furnished with a jet pump and an additional pump both installed between the first-stage separator and the suction side of the pump. In this case an evacuated medium inlet of the jet pump is connected to the first-stage separator, a nozzle of the jet pump is connected to the discharge side of the additional pump, an outlet of the jet pump is connected to the suction side of the additional pump, the discharge side of the additional pump is connected to the suction side of the pump.
The apparatus can be also furnished with a make-up supply conduit, a water discharge pipeline and an additional jet pump installed between the inlet separator and the first-stage separator. If this is the case, the make-up supply conduit is connected to the nozzle of the jet pump, the water discharge pipeline is connected to the inlet and first-stage separators, a nozzle of the additional jet pump is connected to the discharge side of the additional pump, an evacuated medium inlet of said additional jet pump is connected to the inlet separator, and an outlet of the additional jet pump is connected to the first-stage separator.
And finally, the pumping-ejection apparatus can be furnished with a conduit for discharging a surplus amount of the motive liquid and the device for feeding the hydrocarbon condensing liquid to the condenser-separator can be connected to this discharge conduit.
Research of the processes, which took place during gas evacuation, gas compression and during maintaining a vacuum in an evacuated reservoir, has shown that the combined application of a steam-gas ejector and liquid-gas ejectors ensures a more effective operation of the pumping-ejection apparatus if compared with separate usage of these types of jet devices. Availability of a steam ejector allows separation of water steam and easy-condensable components (easy-condensable hydrocarbon gases, for example) from an evacuated gas straight-on during the initial stage of the process. On the same stage of the process it is possible to arrange discharge of water from the apparatus and delivery of a condensate of the hydrocarbon gases into the loop of motive liquid circulation. Thus several problems are solved at once: a motive liquid is refreshed by a cognate medium, entrainment of the condensate of the hydrocarbon gases by water to a sewerage system is prevented and, as a result, environmental safety of the apparatus is provided. Discharge of a portion of the water constituting steam condensate from the counter-flow condenser-separator makes the operation of the condenser more stable and increases its capacity due to a drop in content of the is steam condensate in the upper section of the condenser. A decreased content of the steam condensate makes boiling-up of the condensate in the zone of reduced pressure of the condenser impossible. As a result, it is possible to reduce consumption of the condensing liquid on the one hand and, on the other hand, to reduce flow resistance of the condenser and to avoid steam xe2x80x9cplugsxe2x80x9d in it.
Availability of the additional jet pumps and the additional pump provides a wider range for adjustment of pressures in the separators and, at the same time, ensures transfer of the motive liquid between the separators. As a result, the pumping-ejection apparatus becomes more reliable.
Thus, the described pumping-ejection apparatus implementing the introduced method provides more effective and reliable evacuation of gaseous mediums.